Why we are attracted to "Muft" (free) and "Gupt"(secret ) words ?

No matter whether we are rich , middle class or average, we are attracted to the word muft that means free. Taking this weakness as granted in every one the companies and even government fools the public through their Muft offers and later we are bound to pay by taxes or other means. Like wise when some one says that our revelations and sayings against others will be kept Gupt or secret, we cannot believe that. Our government said that those who deposit their black money the names would be kept secret, But we can always have the names when the situation turns hostile for the government.